Callers to a customer help line frequently complained about the quality of service. Seventy percent of survey respondents cited the services agents' lack of knowledge of how to solve the problems they were calling about. To address the problem, management decided that each service agent should go through regular training. Each agent spent half a day each week in sessions covering how to respond to callers' problems. Nevertheless, after three months of training, the rate of caller complaints has not decreased.
Which of the following, if true, most helps to explain why the training failed to achieve its goal?